Gorean society has a firmly established Caste system, a very important aspect of their society. Almost every Free Person of the cities of Gor belongs to a Caste. Priest-Kings, slaves and outlaws are the three primary exceptions who stand outside of the Caste system. Priest-Kings are considered the gods of Gor and slaves are considered property and thus they have no status in the Caste system.

Caste is primarily governed by birth and children always take on the Caste of their father. Though upward mobility in the Caste system is infrequent it is still possible. In general, few Goreans try to raise their Caste. It would be even rarer for a Gorean to willingly lower his Caste. One way to change Caste for a woman is through Free Companionship. Normally, mating remains within the same Caste. But, in a Free Companionship a woman is permitted to take the Caste of the man if she so desires. This can serve to raise her caste, even from a Low Caste to a High Caste. But, a man cannot take on the Caste of his Free Companion. A person's abilities can also serve to raise their Caste though on the same hand, a lack of ability can lead to a demotion in your Caste. To change one's caste, the High Council of the city must approve the change based upon your qualifications for the new Caste. The new Caste must also be willing to accept you. Proper bribes can make this process easier, even if your qualifications may be lacking. Men and women are generally promoted and demoted by the same criteria in the Caste system. In practice, few Goreans actually change their Caste because they are proud of their Caste, cognizant that each Caste performs a valuable service for the community. Even the Peasant, the lowest of all the Castes, realizes that without their efforts many people would not be fed

Except for the Assassin Caste, you must belong to a Home Stone to have a Caste. Each city has their own Caste system and each specific Caste has its own hierarchy particular to that city. Almost the only time that people from the same Caste, but of different cities, might ever meet to discuss Caste issues is at the Sardar Fairs. The Sardar Fairs are a very important time for the different Castes to share information. You cannot belong to a Caste in a city unless you also belong to the Home Stone of that city. In addition, you may only belong to a single Caste. Dual Castes are not permitted on Gor. Caste loyalty is far too important on Gor for someone to have dual loyalties by belonging to multiple Castes. Now, if one changes their Caste they obviously do not lose any knowledge or skills they acquired from the first Caste. But there might be some restrictions on their use of those previously acquired skills. For example, a Physician who became a Warrior might not be permitted any longer to operate in hospitals owned by the Physician's Caste. But, that Physician would still retain his medical knowledge and skills

Castes also do not have complete monopolies over some of their skills. For example, any person can buy and sell slaves, not just a member of the Slaver's Caste. Anyone can learn how to wield a sword, not just a member of the Warrior's Caste. Obviously such individuals will not know or follow the Caste Codes of those Castes. In addition, there would be some restrictions on their use of those skills. A Caste would not generally permit someone to try to usurp their Caste to a major degree. Goreans also realize that commonly someone cannot practice the work of their Caste until they have satisfactorily completed an apprenticeship. This serves in part as a guarantee to the quality of the product. This guarantee would not apply to a person practicing the skills who does not belong to the Caste. It would be a matter of caveat emptor.

The Caste system is divided into High Castes and Low Castes. The High Castes are considered socially superior to the Low Castes. There are only five High Castes and include, in order of status and importance, the Initiates, Scribes, Builders, Physicians and Warriors. The Low Castes includes all of the other established castes. They are ranked in order of importance as well though

this hierarchy is not clearly defined in the books. We do know that the Peasant Caste is the lowest Caste in the system. Some of these Castes, High and Low, also contain a number of subcastes. The lines between Caste and subcaste is sometimes vague and the subcaste may consider itself to be a separate Caste though legally it is not. Each Caste has its own Caste colors and some subcastes also have their own Caste colors. These colors are often publicly worn as people are proud of their Caste. A person may own documents that certifies their Caste status which can be beneficial if the person is seeking Caste benefits